This invention relates to offshore launching of satellites and other payloads, and more particularly to a method using offshore oil-drilling type of equipment for assembling, transporting and launching of missiles or rockets.
The possibility of launching rocket vehicles for placing payloads such as communications satellites or the like into earth orbit from offshore locations has long been considered, and various investigations have been made of facilities for offshore launch. Land-based launch facilities are of course preferred because of the accessibility and ease of moving and supporting large and heavy equipment around the launch site, stability of the launch site, less severity of weather problems, etc. A land-based launch site is usually near the shore, however, so the trajectory can be over water instead of over populated areas. The availability of large, essentially undeveloped coastal land for these purposes is very limited. Even when suitable land is available, other concerns such as use of corrosive chemicals in environmentally-sensitive areas, noise pollution, air pollution, preservation of historic sites, and the like, have prevented use of such land for launching facilities.
Due to these problems with on-shore launch, investigation of methods and equipment for offshore launch has been an on-going endeavor. For example, R. G. LeTourneau, Inc. prepared a detailed study for the George C. Marshall Space Flight Center, entitled "Offshore Launch Facilities Study", responding to RFP No. TP 88-296, dated 2 June 1961, which proposed the use of a launch platform similar to the sea-bottom-supported, self-elevating platforms employed for offshore oil drilling and production (this type of platform is commonly referred to as a "jack-up" rig). An equatorial launch site off the coast of Kenya used a sea-bottom mounted platform for launch of a Scout rocket in 1967 by NASA and the Italian Government; this was called the San Marco Range. Also, various floating vessels have been proposed such as that seen in U.S. Pat. No. 4,747,334 where a floating-island launch pad is shown using a semi-submersible hull for transporting the launch pad. None of these prior proposals have resulted in construction of viable launch facilities, however, due to expected problems in stability of the vehicles during assembly of the space vehicles or rockets, sensitivity to weather and seas, cost of support vessels needed, and the like.
It is therefore the principal object of this invention to provide an improved method for offshore launching of rockets or space vehicles. Another object is to provide improved equipment and facilities for space vehicle launching which will be of greater stability, lower cost, and/or environmentally acceptability. Still another object is to provide an offshore launch system in which there is no need to transfer a rocket vehicle at sea from a vessel to another vessel or structure, or no need for critical docking or mating of vessels at sea to transfer a rocket. A further object is to provide equipment and methods for offshore launch which will be more suitable (compared to semi-submersible platforms) for handling large and relatively fragile rocket engines, rocket fuel containers and space vehicles. An additional object is to provide an offshore launch system and facility that will allow flexibility in launch location, especially to permit selection of polar or equatorial orbits, yet permitting the use of only one on-shore support arrangement and one offshore platform, resulting in economy and also in less time needed for changing configurations. Similarly, an important object is to provide a "universal" type of offshore launch facility, i.e., one capable of launching many different types and sizes of rockets without major reconstruction; for example, a mobile pad for supporting the assembled rocket may be of various sizes depending upon the size and type of rocket being launched, but the remaining structures used in the launching system would all stay the same. It is an overall objective to provide an economically viable offshore launch facility and method.